Americans increase their risk of cancer practically every time they draw a breath, according to a groundbreaking federal project that finds there is almost no place to escape toxic chemicals in the air. The Environmental Protection Agency found that virtually every American inhaled slightly unsafe levels of at least eight chemicals. Twenty million faced at least a 1-in-10,000 lifetime risk of getting cancer as a result in 1990, the most recent data available for the agency's Cumulative Exposure Project.
The EPA last month abruptly shelved plans to release community-level results after the U.S. Conference of Mayors and state officials objected that the eight-year-old data do not reflect progress in the fight against air pollution.
But officials in states such as Vermont that already aggressively monitor chemicals in the air say the EPA findings remain broadly accurate today. Environmentalists suspect that critics are most nervous about the political impact of a report on pervasive toxic-chemical pollution.
``Many people will be surprised by the relatively high level of health risk associated with air toxics in their area,'' said Bill Pease, a toxicologist at the Environmental Defense Fund who obtained the EPA results under the Freedom of Information Act. ``There are a lot of activities we engage in on a daily basis and don't think they have a toxic consequence.''
N.C. industries released 81 million pounds of toxic chemicals into the air, land and water in 1996, according to separate data, the government's Toxics Release Inventory. An analysis of that data by the Environmental Defense Fund ranked North Carolina in the top 20 percent of states for air and water releases of recognized carcinogens.
Industries in South Carolina released 49 million pounds of toxics, according to the 1996 report. The EDF ranked South Carolina in the top 20 percent of states for cancer hazards those releases pose.
The EPA project marks the first time that researchers have estimated Americans' exposure to scores of toxic chemicals released by industry, automobiles and businesses such as dry cleaners. Unlike most air pollution studies, which focus on a handful of regulated chemicals such as lead and ozone, the agency looked at 148 less well-understood chemicals, such as formaldehyde, that few communities regularly monitor.
EPA researchers estimated chemical concentrations for all 60,803 U.S. Census tracts. They then compared those levels against the amount that would cause cancer or other illnesses in at least one person out of a million during a 70-year lifetime of exposure.
The results, summarized on the EPA's Internet home page -- www.epa.gov:80/oppecumm -- suggest a remarkably widespread pollution problem. Virtually every census tract had elevated levels of at least eight chemicals that can cause cancer or other illnesses, with an average of 14 elevated chemicals per tract.
The EPA found that in 10 percent of the census tracts, residents face at least a 1-in-10,000 risk of getting cancer just from breathing toxic chemicals. Though the risk seems relatively small -- the lifetime risk of dying from smoking a pack of cigarettes a day is one in seven -- it translates into at least 2,000 extra cancers a year in the high-exposure communities alone.
Moreover, even if all pollution stopped tomorrow, EPA researchers found, Americans would still breathe worrisome levels of eight chemicals because of past pollution as well as natural sources. For example, chemicals such as carbon tetrachloride, a now-banned dry-cleaning fluid that can cause cancer, remain in the air for decades after they are released.
In addition, potentially toxic levels of these chemicals are present throughout the country: Bis(2-ethylhexyl) phthalate, benzene, chloroform, ethylene dibromide, ethylene dichloride, formaldehyde, and methyl chloride.
EPA officials were ready to put their exposure data on their home page last month, including estimated chemical levels by census tract, when agency sources say a complaint from the U.S. Conference of Mayors gave the EPA second thoughts.
Kevin McCarty, assistant executive director for the mayors' group, said the toxic-air review is based on data that are too old and too dependent on computer projections to be reliable, making them open to abuse. He said real estate brokers could wrongly steer home buyers away from ``contaminated'' neighborhoods, while urban development projects could be undercut by false fears of poor air quality.
He said the EPA should wait for newer 1996 air emissions data, expected later this year, that may show the air is getting cleaner. The data could then be fed into the EPA researchers' computer model to estimate Americans' exposure levels, a process that EPA sources say would take until 2000.
In response, EPA officials indefinitely shelved plans to release the project's findings while they reviewed them. Now, they say they plan to release the census tract information to those who request it, but they say the 1990 study was intended simply to test its computer models.
``EPA strongly cautions that the results of this modeling exercise alone should not be used to draw real-world conclusions about current local conditions,'' EPA associate administrator Loretta Ucelli said in a statement.